During replacement metal gate (“RMG”) development, a residual carbonaceous contaminant may be formed during a photo-resist step. Conventional residual resist removal may not be a viable option due to the need to leave resist in another, desired location.
Oftentimes, the carbonaceous contaminant is embedded within a void region of a trench oxide (“TO”), which makes removal by conventional etching procedures, for example, the chemical oxide removal (“COR”) process, difficult. In fact, the presence of the carbonaceous contaminant prevents complete oxide removal.
There is thus a need for a process by which an oxide material may be selectively removed, in the presence of a carbonaceous contaminant, with or without damaging other layers or structures on substrate, such as a photo-resist layer.